Practical Antenna Handbook

Joseph J. Can-George W. Hippisley

Fifth Edition

Mc Graw Hill

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Contents

Preface xi Acknowledgments xv

Part I Background and History

1 Introduction to Radio Communication 3

Part II Fundamentals

2 Radio-Wave Propagation 9 Radio Waves 9 The Electromagnetic Wave: A Brief Review 13 Isotropic Sources 17 The Earth's Atmosphere 20 EM Wave Propagation Phenomena 22 Propagation Paths 26 Ionospheric Propagation 45 Propagation Predictions 76 The Magic of Radio 79

3 Antenna Basics 81 Circuit Fundamentals 81 Fields 87 The Hertzian Dipole 92 The Half-Wave Dipole 96 Standing Waves 98 Velocity of Propagation and Antenna Length 104 Antenna Resistance and Losses 107 Half-Wave Dipole Feedpoint Impedance 107

4 Transmission Lines and Impedance Matching 109 Types of Transmission Lines 110 Transmission Line Characteristic Impedance 114 Other Transmission Line Characteristics 118 Transmission Line Responses 121 Standing Wave Ratio 133 Impedance Matching in Antenna Systems 138

5 Antenna Arrays and Array Gain 149 All-Driven Arrays 149 Parasitic Arrays 161 Ground Effects 163

V

vi P rac t i ca l Antenna Handbook

Part III High-Frequency Building-Block Antennas

6 Dipoles and Doublets 175 The Dipole Feedpoint 178 The Dipole Radiation Pattern 182 Tuning the Dipole Antenna 184 Other Dipoles 187 Summary 205

7 Large Wire Loop Antennas 207 X/2 Large Loops 207 IX, Large Loops 209 2X Bisquare Loop Antenna 215 Near-Vertical Incidence Skywave (NVIS) Antenna 216

8 Multiband and Tunable Wire Antennas 217 Multiband Antennas 217 Tuned Feeder Antennas 221 Longwire Antenna 225 Off-Center-Fed Dipole 225

9 Vertically Polarized Antennas 229 Vertical Dipole 230 Grounded Vertical Monopole 232 Elevated Ground-Plane Antenna 248 Vertical versus Horizontal Polarization 248 Supporting the Vertical Antenna 249

Part IV Directional High-Frequency Antenna Arrays

10 Wire Arrays 253 Longwire Antennas 253 Arrays of Longwires 258 Bobtail Curtain 262 Half-Square 263 20-m ZL-Special Beam 264

11 Vertical Arrays 265 Directivity and Phasing 266 Two-Element Array 266 360-Degree Directional Array 272 Four-Square Array 273 Receive-Only Vertical Arrays 274 Grounding 275

C o n t e n t s vjj

12 The Yagi-Uda Beam Antenna 277 Theory of Operation 279 Three-Element Yagi Antennas 282 Yagi Antennas with Four or More Elements 286 Yagi Construction 286 Wire Yagis 297 Multiband Yagis 299 Yagis with Loaded Elements 301 Feeding the Yagi 302 Moxon Beam 306 Stacking Yagi Antennas 308 Rolling Your Own 313 Further Reading 314

13 Cubical Quads and Delta Loops 315 Cubical Quad 315 Delta Loop 325 Diamond Loop 327 Concluding Thoughts 328

Part V High-Frequency Antennas for Specialized Uses

14 Receiving Antennas for High Frequency 331 Beverage or "Wave" Antenna 332 Phased Beverages 340 Snake or BOG Antenna 341 Receiving Loops 341 The EWE Antenna 358 Pennants, Flags, and the K9AY Loop 359 Longwire Antennas 360

15 Hidden and Limited-Space Antennas 363 Hidden Antennas 363 Limited-Space Antennas 368

16 Mobile and Marine Antennas 375 Mobile Antennas for VHF and UHF 375 Mobile Antennas for HF and MF 376 Marine Radio Antennas 383

17 Emergency and Portable Antennas 389 Improving Radiator Efficiency 391 Reducing Ground Losses 391 Selecting the Right Polarization 394 Temporary Supports 395 Summary 398

Pract ica l Antenna Handbook

Part VI Antennas for Other Frequencies

18 Antennas for 160 Meters 401 Vertical Monopoles 401 Horizontal Antennas 415 Inverted-L Antennas 416 Receiving on the Transmit Antenna 423

19 VHF and UHF Antennas 425 Ground-Plane Vertical 426 Coaxial Vertical 427 %-Wavelength 2-Meter Antenna 429 J-Pole Antennas 430 Collinear Vertical 430 Grounds for Ground-Plane Verticals 433 Yagi Antennas 434 Halo Antennas 436 Quad Beam Antennas 436 VHF/UHF Scanner Band Antennas 438 VHF/UHF Antenna Impedance Matching 440

20 Microwave Waveguides and Antennas 447 Waveguides 447 Microwave Antennas 471

21 Antenna Noise Temperature 491 Noise Factor, Noise Figure, and Noise Temperature 492

22 Radio Astronomy Antennas 497 General Considerations 497 Listening to "Ol' Sol" 498 Signals from Jupiter 498 Ring Antenna 500 DDRR 503 Helical Antennas 505 Multiple Helical Antennas 506 Interferometer Antennas 508

23 Radio Direction-Finding (RDF) Antennas 511 Field Improvisation 515 Loop Antennas for RDF 516 Sense Antenna Circuit 517 RDF at VHF and UHF 518 Fox Hunting 518 Shortwave and AM BCB "Skip" RDF 520 Doppler RDF Antennas 524 Wullenweber Array 525 Time Difference of Arrival (TDOA) Array 525

C o n t e n t s ix

Switched-Pattern RDF Antennas 528 Summary 529

Part VII Tuning, Troubleshooting, and Design Aids

24 Antenna Tuners (ATUs) 533 ATU Circuit Configurations 534 Transmatch Circuit 538 Baluns 540 Ferrite Core Inductors 541

25 Antenna Modeling Software 545 Under the Hood 545 ATypical NEC-2 GUI 549 Recently Added Features 554 Other Considerations 555 Terrain and Propagation Modeling Software 556 Summary 557

26 The Smith Chart 559 Smith Chart Components 559 Smith Chart Applications 573

27 Testing and Troubleshooting 587 A Review of SWR 588 Impedance Bridges 590 RF Noise Bridges 592 Dip Oscillators 598 RF Wattmeters and VSWR Meters 602 SWRAnalyzers 612 Vector Network Analyzers 617 Dummy Loads 619 Documenting Antenna System Measurements 621

Part VIII Mechanical Construction and Installation Techniques

28 Supports for Wires and Verticals 625 Antenna Safety 625 Wire Antenna Construction 628 Supporting the Wire Antenna 638 Installing Vertical Antennas 645

29 Towers 653 Types of Towers 655 Tower Fundamentals 655 Guyed Towers 660

X P r a c t i c a l A n t e n n a H a n d b o o k

Bracketed Towers 663 Foldover Towers 664 Crank-up Towers 665 Self-Supporting Towers 667 Tower Bases 669 Guy Wires and Anchors 671 Erecting the Tower 675 Rotators, Masts, and Thrust Bearings 677 Preowned Towers and Accessories 681 Required Reading 681

30 Grounding for Safety and Performance 683 Grounding for Lightning Protection 683 Grounding for Power Distribution Safety 689 Station Grounding 690 Grounds for Antenna Efficiency 692

31 Zoning, Restrictive Covenants, and Neighbors 699 Public Sector Restraints 699 Private Sector Restraints 703 Final Thoughts 703 For Additional Reading 704

Appendices Appendix A Useful Math 707 Appendix B Suppliers and Other Resources 727 Index 745